Merge remote-tracking branch 'goog/upstream-master'.

The following commits were reverted:
840703a Fix update over cellular network on guest account
eaad5d0 Do not merge to AOSP: Fixes the link to brillo-clang-format in CrOS
740efad Reboot even if a system update is not available.

Fixed a few sign compare warnings.
Had to ifdef out 2 SquashfsFilesystemTest because it depends on unsquashfs -m.

Test: update_engine_unittests
Change-Id: I6f4ca5003e78c76064ec60d0797505d8c18d00bf
Merged-In: I6f4ca5003e78c76064ec60d0797505d8c18d00bf
diff --git a/hardware_android.cc b/hardware_android.cc
index 5872c54..58c68b6 100644
--- a/hardware_android.cc
+++ b/hardware_android.cc
@@ -28,7 +28,6 @@
 #include <android-base/properties.h>
 #include <base/files/file_util.h>
 #include <base/strings/stringprintf.h>
-#include <brillo/make_unique_ptr.h>
 
 #include "update_engine/common/hardware.h"
 #include "update_engine/common/platform_constants.h"
@@ -97,7 +96,7 @@
 
 // Factory defined in hardware.h.
 std::unique_ptr<HardwareInterface> CreateHardware() {
-  return brillo::make_unique_ptr(new HardwareAndroid());
+  return std::make_unique<HardwareAndroid>();
 }
 
 }  // namespace hardware
@@ -195,4 +194,14 @@
   return false;
 }
 
+bool HardwareAndroid::GetFirstActiveOmahaPingSent() const {
+  LOG(WARNING) << "STUB: Assuming first active omaha was never set.";
+  return false;
+}
+
+void HardwareAndroid::SetFirstActiveOmahaPingSent() {
+  LOG(WARNING) << "STUB: Assuming first active omaha is never set.";
+  return;
+}
+
 }  // namespace chromeos_update_engine